Denotes a sudden, rapid, short-term effect (e.g. a fast occurring toxic effect).

General term for mixtures of gases (e.g., air) that contain suspended solid or liquid particles (so-called particulate matter) which are approximately 1 nm to 10 μm in diameter. Sea salt aerosols, for example, are formed as sea water droplets that are dispersed into the atmosphere by wind evaporate to leave sea salt particles.

atomic force microscopy. The AFM tip scans the sample line for line. Due to repulsion between needle and sample, a movement of the tip is detected. A three dimensional image can be simulated.

Accumulations of weakly bound particles or aggregates or of compounds of these, whose resulting surfaces are similar to the sum of surfaces of the individual components. Agglomerates are held together by weak forces, for example Van der Waals forces or simple physical hooks. Agglomerates are referred to as secondary particles, while the unbound particles are known as primary particles.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

Solidly bound or molten particles, whose resulting surface may be much smaller than the sum of the calculated surfaces of the individual components. Aggregates are held together by strong forces such as covalent bonds or forces caused by sintering or complex physical hooking. Aggregates, just as agglomerates, are referred to as secondary particles.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

from Latin alveolus, "little cavity". Thin-walled, tiny air sacs, located at the ends of the smallest airways in the lungs (the bronchioles) where the exchange of oxygen and carbon dioxide takes place.

any substance that prevents or reduces free-oxygen-radicals which attack other molecules and modify their chemical structure. Antioxidants are commonly used as preservatives in food or cosmetics. Well-known antioxidants include vitamins A, C, and E.

physiological or programmed cell death. In apoptosis only individual cells are affected generally and these react to internal signals (e g adjacent cells) or external stress situations. At the beginning of this process the cell nucleus, cytoplasm and mitochondria are shrinking; the cell membrane remains undamaged, so that no inflammatory reaction occurs. The biochemical indicator of apoptosis is the fragmentation of DNA. Along with proliferation the apoptosis is the common instrument to stabilise the cell count.

Description of a method (Brunauer-Emmett-Teller) for the analysis technique of sizing surfaces by means of gas adsorption.

Molecules or structures acting as indicators for environmental stress or disease, for example in medicine or biology. Characteristic biological features that can be objectively measured and indicate a normal biological or pathological process in the body.

Literal meaning „from bottom to top“. Production process starting from small units (from atoms, for example, in nanotechology).

or Buckyball, these are other terms for the carbon compounds described under fullerenes. They are derived from the name of Buckminster Fuller, the ”inventor“ of the fullerene structures.

A substance, an organism or a radiation that causes or promotes cancer.

The property of nanomaterials to penetrate cell walls or membranes due to their small size is referred to as cell penetration capacity.

Denotes a slowly occurring or long-lasting effect (e.g. toxic effects occurring only after long exposure time or a protracted inflammation).

is a covering that is applied as a thin film to the surface of an object, e.g. nanoparticles. Coatings are applied to improve surface properties of the nanoparticles, such as solubility, adhesion, wetability, and corrosion resistance, and to reduce dissolution of ions. Frequently used coatings in nanotechnology include polymers, lipids (medical applications) or metals (catalysts).

Very small solid particles (typically smaller than 10 µm) suspended in a solvent. Compared with solids in suspensions, solids in a colloid do not precipitate, i.e. do not sink to the bottom of a vessel. In liquids, colloids are recognized by clouding and/or the so-called Tyndall effect.

Collective term for measures related to volume, e.g. g/ml, kg/l, g/cm³. Due to their high surface/volume ratio, for nanoparticles instead of mass-related, surface-related concentration ranges, e.g. cm²/ml is frequently used.

describes the regular arrangement of atoms or molecules in a crystal lattice. Different lattice structures of the same material (e.g. titanium dioxide) give nanoparticles different chemical and physical properties (e.g. photocatalytic activity).

to deposit, marks the deposit of solid, liquid and gaseous particles in the organism

Physical process leading to the mixing of different gaseous, liquid or solid substances theat are in contact with each other.

from Latin dispersus. In chemistry: the mixing of two substances that cannot dissolve each other completely or react with each other completely.
In physics: Dependence of the propagation of waves on wavelength. Example: Decomposition of white light into light of different colours by a prism.

Materials that are impurified during production with small parts of another material (intentional impurification) are referred to as doped materials. Such traces of other elements can decisively affect the properties of a material, as, for example, is the case with different types of steel. In nanoparticles, individual atoms can be replaced by other atoms.

Term for the amount of a substance, which acts within a specific time or to a specific organism (see also LD50). In toxicity testing of nanoparticles, dose information, such as number of particles/cell or µg particles/cm² surface area are used.

derived from the Greek terms epi = upon, among; demos = people, district; logos = study. "The study of what is upon the people", Scientific studies are dealing with the reasons, impacts and extension of health related substances in populations. Epidemiological studies show impacts of toxic substances on the human population, often unintended by incident.

means to expose an object to a particular influence: In the case of nanomaterials, in particular, the contact of humans, animals or the environment with the possibility of incorporating nanomaterials. Both the quantity and the period of ingestion are of concern. For more information, see the Knowledge Base Nanomaterials - Basics - Exposure.

Latin: "out of the living", procedures or processes, in which living biological material, in particular cells, tissues or organs taken from a living organism and cultured outside of that. This will allow treatment and analysis of the material under controlled conditions.

Atoms or molecules that contain one or several unpaired electrons and, in that sense, are „free“. Correspondingly, any free radical has an electron that stands alone. Many free radicals are highly reactive, meaning that they have a strong tendency to arrange in pairs and, thus, escape the instable unpaired condition. For pairing, free radicals randomly receive electrons from a suitable donor or donate electrons to an appropriate aceptor which converts into secondary free radicals. Such chain reactions may cause biological damage. 

Genotoxic effects are damages to the genetic material of organisms (DNA). They can lead to mutations or increase the error rate in the doubling of DNA at each cell division. Genotoxicity is therefore not necessarily associated with mutagenicity.

describes the resistance of a solid material against penetration of another solid body. It is determined by means of scratching (Mohs hardness number in geology) or by indentation methods (materials science) which differ with respect to the indenter and the load regime (Vickers, Rockwell, Knoop, Berkovich). They deliver different hardness figures.

science concerned with the study of microscopic changes in diseased tissues.

from the Ancient Greek hydor "water" and philia "love”, water-loving. Describing the character of a molecule, a substance or a surface, which has an affinity to water.

from the Ancient Greek hydros "water" and phobos „fear“, water repelling. Describing the character of a molecule, a substance or a surface, which has a low affinity to water.

Typical response of animal tissues to potentially damaging stimuli e.g. by physical stimuli (pressure), chemical stimuli (heat or cold), or by micro-organisms (viruses, bacteria), with the function to remove this stimulus and to prevent its spread. Some technical nanoparticles are suspected to cause inflammations because of their bacteria- and virus-like particle shape, e.g. by inhalation of very high TiO₂ concentrations in the lung.

means the simulation of biological and biochemical processes using computer programs.

Administration of (particle-)suspensions into visceral cavities or hollow organs (e.g. nose, throat) of an organism.

“In the test tube”, from the Latin vitrum – glass, referring to reactions outside the organism, sometimes under participation of autologous physiological conditions.

from the Latin vivus – alive, characterising reactions or processes that take place in the living organism under physiological conditions.

also IEP, pI or point of zero charge, is an important parameter for assessing the behaviour of nanoparticles in aqueous surroundings. The IEP is the pH of an aqueous suspension, where the positive and negative charges on the particle surfaces are balanced. The IEP for each particle type is individually different and an important material parameter to assess the stability of particles in suspension.

french, from lat. lavare „to wash“. Medical procedure. Irrigation or washing out of a hollow organ or cavity such as the stomach, intestine or the lung.

Lethal dose. Concentration of a substance that leads to death of 50% of the organisms exposed to it.

systematic analysis of the environmental impacts of products throughout the life cycle ("cradle-to-grave").

from the Ancient Greek lipos "fat“ and philia "love”, fat-loving, having an affinity to fat and high lipid solubility.

from the Ancient Greek lipos "fat“ and phobos "fear“, avoiding fat, having a low affinity to fat and a high affinity to water.

Lowest observed effect level.

gr. from makros "large" and phagein "eat". Big eaters, cells of the immune system, serve to eliminate microorganisms or particles by phagocytosis; especially in areas of inflammation.

Is the simulation of different processes (biochemical processes in cells, material flows of nanoparticles in ecosystems) using especially developed computer programs. By changing relevant parameters of a process, modelling allows predictions and saves laborious experiments.

* MTT: Abbreviation for the dye compound 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor
measuring the functionality of animal and human cells. Colorimetric assay for measuring the activity of enzymes that reduce MTT or close dyes.

describes the capacity of certain chemicals or high energy radiation to cause changes in the genetic material (DNA), known as mutations.

Nano-object with two similar external dimensions in the nanoscale and a third significantly larger.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

On 18 October 2011 the EU Commission adopted the Recommendation on the definition of a nanomaterial.
According to this Recommendation a "Nanomaterial" means:
A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 % or more of the particles in the number size distribution, one or more external dimensions is in the size range 1 nm - 100 nm.
In specific cases and where warranted by concerns for the environment, health, safety or competitiveness the number size distribution threshold of 50 % may be replaced by a threshold between 1 and 50 %.
By derogation from the above, fullerenes, graphene flakes and single wall carbon nanotubes with one or more external dimensions below 1 nm should be considered as nanomaterials.

Material with one, two or three external dimensions in the nanoscale. This is a generic term for all nanoscale objects.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

Nano-object with all three external dimensions in the nanoscale.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

Nano-object with one external dimension in the nanoscale and two other external dimensions significantly larger.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

or nano-scale, size range from approximately 1 nm to 100 nm.

from the Ancient Greek nékrosis "dead". Mass death of areas of tissue or organs surrounded by otherwise healthy tissue.

no observed (adverse) effect level.

no observed effect concentration.

latin noxa – damage, every harmful effect on man and/or environment.

definable structure within a cell with a specialised function.

results from an imbalance between the intracellular production of free radicals and the cellular defense mechanisms. The balance between oxidants and antioxidants may be disturbed by the increase in free radicals or the reduction of antioxidant substances. Oxidative stress may cause destructive biochemical reactions.

from the Ancient Greek pathos "suffering“ and genesis "origin“, a disease causing. All substances or organisms that can cause a disease are summarised as pathogens.

Predicted Environmental Concentration, is a theoretical value giving an indication of the expected concentration of a material (e.g. nanoparticles) in the environment (exposure assessment). The calculation takes into account the amount initially present (or added to) the environment, its distribution in the different environmental compartments, and the probable rates of environmental degradation and removal, either forced or natural.
Modified after http://msds.chem.ox.ac.uk/glossary/pec.html

In biology and environmental chemistry, the term “persistence” denotes the property of substances to persist in the environment over long periods of time while remaining unchanged by physical, chemical or biological processes.

Latin, short for pondus/potentia Hydrogenii (weight/power of hydrogen). Dimensionless measure of the acidic or alkaline (basic) reaction of an aqueous solution. The pH of a nanoparticle suspension affects the behaviour of particles in the solution (agglomeration, solubility, suspensibility).

(Greek phagein = to eat). Mechanism of uptake from particles to small cells in a single eukaryotic cell. Usually, particles are taken up by the cells as membrane-bound aggregates, i.e. large aggregates in vesicles, vacuoles or lamellar bodies (cell compartments surrounded by membranes) through phagocytosis. In mammals, phagocytosis is performed mainly by special cells of the immune system, including the macrophages, monocytes (precursor cells of macrophages), and neutrophils (or neutrophilic granulocytes, belonging to the white blood cells). This uptake is an active, regulated process.

Ability of some nano materials (e.g. TiO₂) to speed up a certain reaction ("photoreaction") as a catalyst in combination with light (sunlight, ultraviolet light). In the case of TiO₂, for example, influenced by sunlight radicals (see also ROS) are formed, which decompose organic materials. This effect is used for self-cleaning surfaces.

predicted no effect concentration, predicted concentration of a hazardous substance in the environment which shows no impact on the environment (effect assessment). If this concentration is thus below the PNEC, it should not have any negative effects. PNECs find application especially with PECs in the risk quotient in environmental risk assessment.

nanoparticles, which can affiliate to a bigger linked system (agglomerate, aggregate).

crystaline nanoparticle that exhibits size-dependent properties due to quantum confinement effects on the electronic states.
See also ISO/TS 27687:2008 (E), International Organization for Standardization

Registration, Evaluation, Authorization of Chemicals. REACH is the novel EC regulation no. 1907/2006 that has been in force since June 1, 2007. For further information, see http://echa.europa.eu/reach_en.asp

is calculated from an estimated exposure (PEC), divided by an estimated effect (PNEC). If a value less than 1, then there is an acceptable risk. In contrast, if the RQ greater than 1, there is an unacceptable level of risk and measures to reduce exposure should be taken.

reactive oxygen species, the organism considering harmful forms of oxygen, which result from oxidative stress.

from the latin secernere „segregate“. Release of important substances for the organism (for example hormones, digestive enzymes) by specialised cells, especially glandular cells. The substances themselves are called secretions.

Settling of particles from liquids influenced by gravity and other forces, e.g. the centrifugal forces generated in a centrifuge. The sedimentation rate is determined by the particle size and density of the material.

The solubility of a substance indicates whether and to what extent a substance in a solvent (usually a liquid) can be solved. It describes the property of a substance to be evenly mixed with the solvent. Inorganic nanoparticles (mostly metals and metal oxides) decompose into ions. The solubility depends i.a. of temperature and pH of the solution.

superparamagnetic iron oxide nanoparticles.

Auxiliary substances that contribute significantly to obtaining or maintaining a stable condition. This can for example be a certain particle size (preventing the agglomeration), or composition. Commonly used stabilizing agents for nano-materials include citrate, phosphates, or polymers such as polyethylene glycol (PEG).

Refers to a course or effect, which is located between acute and chronic, e.g. a less intense course, in time neither fast nor slow running.

is the electric charge present at the interface of the nanoparticle surface with a polar fluid such as water. The water contains positive and negative ions, which interact with the particle surface. If the number of adsorbed e.g. positive ions exceeds the number of negative ions, surface charge would be positive. Since direct measurement of the surface charge of particles measured is difficult, the zeta potential is calculated as a proxy for the surface charge.

Solid particles suspended in a liquid, i.e. a more or less thick sludge or slurry. Normally, the solid particles deposit on the bottom if one allows the suspension to rest for a while in the vessel.

Transmission electron microscopy. Method for examining the smallest materials by radiographing the sample using electron rays. The wavelength is about 5 nm depending on the configuration of the equipment. The sample to be examined can be enlarged by one million times.

Literal meaning „from top to bottom“. Production process starting from large units and proceeding with comminution (for example, cutting or grinding).

The term “toxicity” denotes the poisonousness of a substance, i.e. its property of developing undesired effects and of impairing functions in cells or living organisms. Effects caused by toxicity may even cause death of the affected organism.

from the Greek words τοξικός - toxicos "poisonous" and logos, study of the adverse effects of poison

From the Latin vesicula – small bubble . Round or oval compartments that are approximately 100 nm in diameter. Vesicles are located in the cells and are surrounded by separating layers (membranes).

also ζ-potential, is the electrical potential at the contact layer of a moving particle with an aqueous solution (suspension). Thus, within the same suspensions, it is a relative measure of the surface potential and thus the charge of the particle. For the measurement of the zeta potential, charged particles are moved through an applied electric field. The resulting speed is then a measure of the zeta potential.